Functional foods, which have also been referred to as nutraceuticals, are foods that promote health and/or prevent disease. Examples of functional foods include, but are not limited to, omega-3 fatty acids (found in many fish, flaxseed oil, soybean oil, canola oil, and walnuts) which reduce risk of coronary heart disease, blueberries which may have anti-aging effects, and lycopene (found in tomatoes) which has been associated with reduced risk of certain cancers.
Many companies are looking for new ways to develop and incorporate functional foods into their products. Currently, functional foods may be incorporated into a product utilizing high-temperature-short-time (HTST) processes, such as extrusion and aseptic processes. These processes generally require tracking of the food temperature. However, when the food temperature is unknown, the thermal properties of the food may be utilized to estimate the food temperature. The thermal properties of the food may be estimated, for example, using an isothermal line-source method. While this method is useful for determining the thermal properties of the food at low temperatures (e.g. temperatures less than 100° C.), this method often poses a challenge when estimating thermal properties at high temperatures (e.g. temperatures greater than 100° C.). This is due, at least in part, to the degradation of the quality of the food as the food is exposed to the high temperatures. In many instances, the nutrients in the food are degraded and the food ends up burned or even charred.
Accordingly, there is a need for a convenient and efficient testing system for estimating the thermal properties of a material (such as food) at temperatures greater than 100° C.